I feel bad for the mysterious entity about to be shot by that shotgun, either for the 3rd or 1st time, depending on how vigilantly she reloads.
Nice work dude!
Anatomically speaking everything seems to be in good order, and while I was going to saw that your lineart was looking too thin on her hand that was tossing the shells, after I enlarged the image to fullsize I saw that you were having the the lineart get thinner the further away it was from the camera.
Cloth crumples are also looking good, so the only thing looking slightly off is the shotgun stock, since it looks like it's slightly bent in regards to the nozzle and base of the shotgun. But hey, guns are always tricky to draw perfectly. haha
Keep it up!